Apparatus for the manufacture of conjugated sheath-core type composite fibers



March 17, 1970 NOBORU FUKUMA ET AL 3,500,498

APPARATUS FOR MANUFAC RE 0F CON ATED v SHEATH-C TYPE 00 SITE FIB 5 FiledMay 26. 1967 3 Sheets-Sheet 1 FIG. 2

March 17, 1970 NOBORU F U AL D3,500,498

APPARATUS FOR THE MANUFACTURE JUGAT SHEATH-CORE TYPE COMPOSITE F ERS 5Sheets-Sheet 2 Filed lay 26, 1967 March 17, 1970 No o u FUK-UMA ET AL3,500,498

- APPARATUS FOR 14 FAGTURE 0F CONJUGATED SHEATH-G TY COMPOSITE FIBERSFiled llay 26. 1967 5 Sheets-Sheet 5 United States Patent Office3,500,498 Patented Mar. 17, 1970 3,500,498 APPARATUS FOR THE MANUFACTUREOF CONJUGATED SHEATH-CORE TYPE COM- POSITE FIBERS Noboru Fukuma, HiroshiChayamichi, Toshio Okamoto, and Hiroshi Henmi, Nobeoka-shi, Japan,assignors to Asahi Chemical Industry Company Limited, Osaka,

Japan Filed May 26, 1967, Ser. No. 641,617 Claims priority, applicationJapan, May 28, 1966, 41/33,875; Aug. 10, 1966, 41/52,111 Int. Cl. D01d3/00 U.S. Cl. 188 5 Claims ABSTRACT OF THE DISCLOSURE (1) A conjugatedsheath-core type composite fiber, wherein the core is arrangedconcentrically with the sheath and composed of two ditferent spinningmaterials conjugated to each other.

(2) A process for the manufacture of conjugated sheath-core type ofcomposite fibers, comprising for each fiber the following steps of:conjoining two different spinning materials so as to form a conjugatedcore; supplying a different spinning material around the thus conjoinedcore mass in a concentric manner so as to form a sheath; and extrudingthe thus conjugated coreand-sheath mass through a discharge opening.

(3) A spinneret assembly for the manufacture of conjugated sheath-coretype composite filaments, having a number of spinneret elements, whereineach of the latter contains a conjugating zone for two differentspinning materials destined for the core; a sheath-forming andconjugating zone to form a concentric sheath around the thus conjugatedcore mass; and an extruding zone for extruding the thus conjugatedcore-andsheath through a discharge opening.

LIST REFERENCES (1) Great Britain, patent specification No. 760,179 ofOct. 31, 1956, granted to Paul Halbig.

(2) Great Britain, patent specification No. 805,033 of Nov. 26, 1958,granted to E. I. du Pont de Nemours and Company, corresponding to US.Patent No. 2,931,091.

(3) Great Britain, patent specification No. 896,955 of May 23, 1962,granted to E. I. du Pont de Nemours and Company.

This invention relates to improvements in and relating to themanufacture of conjugated sheath-core type composite fibers or filamentswhich are permanently crimped or crimpable by virtue of the differentshrinking characteristics of the components of a fiber.

Conventional fiber of the above kind has an eccentric core extending theoverall length of the fiber and having a circular cross-section enclosedby the sheath.

According to our practical experience, however, it is definitelyobserved that the crimping performance of this kind of conventionalfiber is not enough to meet with practical demands.

This deficiency is attributable to such fact that in order to attainenough crimpability it is necessary to provide the core per se with asatisfactory anisotropy in radial directions and regarding itscross-sectional configuration and/or its material composition. When thecore of a composite fiber comprises a sole fiber material and has acircular cross-section as in the conventional technique, although thecore is eccentric to the sheath as referred to above, the per se doesnot represent considerable crimp performance.

Another problem inherent in the conventional fiber or filament residesin the very difficulty in the alteration of the relative cross-sectionalarrangement between the core and the sheath of the fiber. Attaining thiseffect is not absolutely impossible, but, for this purpose a highlycomplicated spinneret must be used. Especially, in this case, a constantrate of feed of the spinning material and that of the extrusion arehighly difiicult to realize. It is therefore the main object of thepresent invention to provide unique and substantially improved compositefibers or filaments of conjugated sheath-core type, capable ofdeveloping higher degree of crimps.

Another object is to provide a fiber of the above kind, having astabilized relative cross-sectional position of the core and the sheath,by means of a highly simplified spinneret assembly.

Still another object of the present invention is to provide a. uniquetechnique for the manufacture of the novel type of fibers of the abovekind.

The novel composite fiber according to this invention and of conjugatedsheath-core type comprises two or more kinds of spinning materials,preferably polymers, copolymers and the like, extruded simultaneouslyfrom a spinneret opening and the core being concentric to the outersheath and having substantially a specifical- 1y intended shape alongthe entire length of the fiber or filament, such as semi-circle,crescent, convex lens or the like, when considering a single filament.

When a composite fiber according to this invention comprises threedifferent kinds of spinning material, the physical composition may be,for instance, such that the core consists of two different materials andconcentrically enclosed by the sheath consisting of the third orremaining spinning material. According to the spinning process and withuse of the spinning apparatus according to this invention, a largenumber of fibers of this highly complicated composite nature provided bythree different spinning materials can be produced in a highlysimplified and efiicient manner, and indeed, in a single extrusionprocess.

As will be seen at a later stage of the description, the novel fiber orfilament is a kind of combination of a conjointed composite fiber with aconjugated sheath r core type fiber.

This kind of fiber or filament is perfectly novel and may representvarious crimp and/or dying characteristics, by properly selectingdifferent spinning materials.

The spinning material employable in this invention comprises one or moreof polymers or copolymers which have fiber-forming property. Thematerial is used in the form of a solution in a suitable solventcommonly employed in the art. 0r alternatively, the material may be inits fused molten state.

As the spinning materials, known and various polymers and copolymers ofpolyamide-, polyester-, polyolefine, polyester ether-, polyacryl-,polyvinyl-chloride, polyvinylidene chloride, polyurethane-, polyureaandthe like series, may be utilized, Cellulose series compounds may also beused.

In order to manufacture the aforementioned novel and improved compositefibers, it is proposed to employ, according to a further feature of theinvention a process for the manufacture of a conjugated sheath-core typecomposite fiber, comprising: conjoining two different spinning materialstogether at an intermediate zone of a 113W passage consisting of aspinneret; leading a further spinning material diiferent in its kindfrom the both or same in its kind as one of said both materials to saidzone or to a downstream zone from said conjoining zone, for theformation of a closed sheath around the conoined mass; and extruding thethus formed sheath-core ombination through a spinneret opening.

It would not absolutely be impossible to manufacture he aforementionednovel and improve composite fibers ay conventional spinning apparatus.In such cases, how- :ver, complicated spinning material ratingappliances are lecessary to employ for supplying core material ormaerials and sheath material in a specific and predetermined elativeratio, in order to produce a specific cross-sectional :onfiguration ofthe composite and conjugated filament ubstantially along its wholelength, especially for the ealization of the required variable, yetpredetermined vall thicknesses of the sheath and for producing a sharp.eparating surface between the core and the sheath. In lddition thereto,pressure regulators are necessarily to 'fit n order to meet theabovementioned complicated maerial delivery requirements. Still further,high precision vorkmanship is necessary in the manufacture of thepinneret, in addition to precisely controlled maintenance :onditions.

For the manufacture of the novel fibers according to his invention andfor obviating the aforementioned diffi- :ulties which must be taken intoconsideration when 'elying upon the conventional spinneret technique,the nvention further proposes a spinneret assembly for the manufactureof conjugated sheath-core type composite ilaments, comprising a numberof spinneret elements ormed in said assembly, each of said elementsbeing :haracterized by the provision of two separate inlet pasages forthe reception of core component materials, anther for outlet extremitiesof said passages being aranged to keep fluid communication with eachother so [8 to form a conjoining zone for said core material; a hirdpassage for the reception of a sheath material; a heath-forming zonearranged concentrically, when viewed n plan, to said conjoining zone andkept in fluid comnunication with the latter as well as said thirdpassage; 1nd a spinneret opening leading from said sheath-formng zone,for receiving from the latter and extruding the :onjugated sheath-core.type conjugated filament of specific .trength.

These and further objects, features and advantages of he presentinvention will appear more specifically in the ollowing detaileddescription of several embodiments of he novel filaments, as well asthose of the apparatus ldopted for the manufacture thereof, saidembodiments )eing shown however only for the illustrative purpose andhus in no limiting sense of the invention.

A preferred spinning apparatus for the manufacture of he said novelfibers or filaments-according to this invenion, there are provided threefeed pumps, preferably of gear type, arranged to deliver three differentkinds of pinning material, two materials of which are conjoined ogetherat an intermediate point or zone formed in the :onduit system providedina spinneret assembly, and a hird spinning material which is fed fromthe third feed lump and may be, under circumstances, same as the firstar second material, as the case may be, is so led within he spinneretconduit at a downstream zone from the said :onjoining zone that it willcompletely enclose said conointed and flowing material, in the form of asheath 1nd a core. Under circumstances, the first and the second:omponent material fed from respective pumps are Irought into joiningtogether, and the third material fed rom the third feed pump is so ledat the very conjoining zone that it encloses the conjoined core mass.

In the drawings:

FIGURE 1 is a top plan view of part of a spinneret lssembly ascomprising only spinneret elements, for L clear representation of thedrawing.

FIGURE 2 is an axially sectional view of the assembly hown in FIGURE 1,taken along a sectional line HII hown therein, together with three feedpumps and related eed pipings shown only schematicall by chain-dottedInes.

FIGURE 3 is a top plan view-of part of the intermediate plate comprisedin the spinneret assembly shown in several foregoing figures. I

FIGURE 4 is a horizontally sectional view taken substantially along asectional line IVIV in FIGURE 2.

FIGURE 5 is part of a top plan view, illustrative of a modifiedspinneret assembly from that shown in the foregoin figures.

FIGURE 6 is an axially sectional view of said modification.

FIGURE 7 is part of a horizontal section of said modification, VIIVII.

FIGURE 8 is part of a top plan view of a still further modifiedspinneret assembly.

FIGURE 9 is an axially sectional view of the second modification shownin FIGURES 8-9.

FIGURE 10 is an enlarged sectional view of the part of FIGURE 9 which issubstantially encircled by a small chain-dotted circle denoted H.

FIGURE 11 is part of a horizontally sectional view, taken substantiallyalong a section line XIXI in FIG- URE 9.

FIGURE 12 comprises several cross-sectional views of several novelfilaments according to this invention, in comparison with that of acomparative conventional filament shown at (M).

Now referring to the drawings, especially FIGURES 1-4 thereof,illustrative of an embodiment of the novel spinneret assembly at 10,embodying the principles of the present invention; numeral 11 denotesupper top plate; 12 intermediate plate and 13 bottom plate, all of saidplates being preferably formed into respective discs of a same diameter,as shown. Upper plate 11 is formed with a plurality of sets of inletconduits 15, 16 and 17, each set of said conduits being bored completelythrough the disc and arranged in a row and all the sets being arrangedpreferably in a radial symmetry, as shown.

Intermediate plate 12 is formed with vertical conduits 1'8 and 20 and ahorizontally extending connecting or conjoining conduit 19 kept incommunication with the lowermost ends of conduits 15 and 16, on the onehand, and with the upper end of conduit 20, on the other. Conduit 18 iskept in communication with conduit 17, as shown. Although not shownspecifically, as equal number of sets of said conduit group 18-20 areprovided, to the number of those of conduit group 15-17. Around thelowermost end of each of said conduits 20, there is a small dependingprojection at 21, these projections being shown only one in FIGURE 2 forsimplicity of the drawmg.

Bottom plate 13 is formed in the upper surface with a number of recesses22, each of which is arranged concentrically with a respective one ofsaid projections 21 and kept in communication with conduits 18 and 20,when three plates 11-13 are assembled together as shown in FIGURE 2.From the center of said recess 22, a further conduit extends verticallythrough the botom plate 13, which conduit comprises a first part 23having a form of an inverted cone and a second part 24 havingsubstantially a cylindrical shape, so as to establish an outlet opening.

As shown in FIGURE 2, three plates 11-13 are assembled together in anoverlapped manner and there are provided a tongue-and-groove centeringmeans 25 or 26 between each pair of said plates 11-12 or 12-13,respectively, for assuring their relative correct position as shown.These plates 11-13 are encased by a cylindrical case 14 which is formedwith an inwardly directing bottom flange 14a adapted to snugly engagewith a shoulder 13a formed on the bottom plate 13, thereby ilipligltingthe assembled and centered plate assembly Conventional metering pump G1,preferably of gear type, is connected through a feed piping to the upperextremity of first inlet conduit 15. In the similar Way,

taken substantially along a sectional line metering pumps G2 and G3,again preferably of gear type, are connected through feed pipings 101and 102 to the upper extremities of second and third inlet conduits 16and 17, respectively. Naturally, the connection between each pair offeed piping and inlet conduits is made by conventional pipe fittingssuch as nipples, although not shown. In FIGURE 2, said pumps and saidfeed pipings are shown only schematically by chain-dotted lines onaccount of their very familiarity.

In the operation of the composite and multi-hole spinneret assembly, afirst spinning material such as polyamide copolymer is fed from thefirst pump G1 through piping 100 to the first inlet conduit 15. At thesame time, a second spinning material such as nylon-6 polymer is fedfrom the second pump G2 through piping 101 to second inlet conduit 16.

Thus, the first and the second spinning materials of different physicalproperties, especially crimp potencies, are led through both inletconduits 15 and 16, respectively, to junction conduit 19 where they areconjoined together, thence through the common conduit 20 and a thin gapformed below the lowermost extremity of the latter conduit into the coneconduit 23. On the other hand, a third spinning material such as nylon66 salt or hexamethlyenediamine adipate is fed from the third pump G3through feed piping 102 to third inlet conduit 17, thence throughintermediate conduit 18 into the recess 22. Thanks to the concentricarrangement of this recess 22 relative to the conduit 20 and dependingprojection 21, the fed third material will occupy the ring space formedaround the latter within the recess 22 and to form a sheath around theconjoined core material injected from conduit 20 into the cone 23. Thethus formed, conjugated sheath-core type composite filament in itsplastic state will be extruded from the outlet opening at 24.

In a modification, shown in FIGURES 5-7, from the foregoing, thespinneret assembly comprises upper or back plate 27, lower or spinneretplate 28 and a case or holder 29, corresponding to that of 14 in theforegoing embodiment.

Upper plate 27 is formed with a group of inlet conduits 30, 31 and 32 asin the same way with those denoted 15-17 in the foregoing embodiment.For positioning the both plates 27-28, there is provided atongue-and-groove connection at 38 between the both for keeping them ina specific relative position.

In correspondence to each of conduit group com-prising conduits 30-32, amaterial-receiving space or recess at 33 is formed in a circle in theupper surface of lower plate 28, the peripheral wall surface at 35 beingin registration with the innermost wall part at 32a of conduit 32. Saidrecess 33 is formed with a concentric circulating projection 34 fordividing the space 33 into an outer ring zone and an inner disc-likezone, said both zones being however kept in communication with eachother through a reduced passage defined by the bottom surface of upperplate 27 and the ring projection 34.

From the center of said inner disc like zone of the material receivingspace 33, a common conduit 36 extends downwards and is connected througha cone-shaped junction to an outlet opening at 37. Although not shown,metering pumps such as those G1, G2 ,and G3 in the foregoing embodimentare connected through respective pipings such as 100-102 to the inletconduits 3032, respectively, as before, although not shown.

In the operation of the present modified spinneret, a first and a secondspinning material of different physical properties are fed fromrespective gear pumps through feed pipings to inlet conduits 30 and 31,thence to the material-reception space 33 and within its central zonedefined by the circular ring projection 34, thus the both materialsbeing conjoined or conjugated together. Simultaneously, a third spinningmaterial having a further different physical property is fed from thethird gear pump through the attributed piping to the third inlet conduit 32, thence into the outer ring zone of said space 33.

This third material will invade into the thinner central zone in such amanner that it encloses the conjoined core mass consisting of the firstand the second material prevailing in the central zone. In this way, aconjugated sheath core type composite filament will be extruded from theoutlet opening 37. Naturally in this case, the core consists of thefirst and second material, while the sheath comprises the thirdmaterial.

The design and operation referred to above in the present modificationrelative to one spinneret element also apply to all other spinneretelements arranged radially as shown in the spinneret assembly.

In a still further modified arrangement shown in FIG- URES 8-ll, upperor back plate 39, lower or spinneret plate 40 and case or holder 41 areprovided in the similar way as in the foregoing first modification.Although the upper plate 39 is again formed with three inlet conduits at42-44, the main difference from the foregoing modification resides insuch that first and second inlet conduits 42 and 43 are joined togetherat their lower ends so as to form a conjoining zone at 45. Anotherdifference comprises the provision of a land 46 defining a ring space 47concentrically with the conjoining zone at 45 as well as dischargeconduit parts 48-49, all being formed in the lower plate 40. Thedischarge conduit 48-49 is formed vertically in registration with theconjoining zone. Centering means of tongue-and-groove type at 50 is alsoprovided between the both plates 39 and 40 as before.

In the operation, a first and a second spinning material are fed from afirst and a second gear pump as before, through respective feed pipingsto the first and the second inlet conduits at 42 and 43, thence toconjoining zone 45 for performing the conjoining of the both corematerials together. Simultaneously, a third spinning material for sheathis fed from a third pump through its attributed feed piping to the thirdinlet conduit 44, thence to the ring space 47. This third material willthen invade from all radial directions into the narrow gap definedbetween the bottom surface of upper plate 39 and the circular land 46,thereby enclosing the conjointed core material passing through thecenter of said gap into the upper enlarged part at 48 of the combinedspinneret conduit including the lowermost discharge opening at 49. Thus,also in this case, a conjugated sheath-core type composite filament isextruded from the discharge opening 49. All other spinneret elementsshown, comprising similar conduits, are of same design and operation andno further description would be necessary for understanding of thepresent modification.

In FIGURE 10, an enlarged sectional view is shown of a part of thespinneret assembly as encircled by a small chain-dotted circle denotedH.

In order to produce a continuous filament of the above kind and having aconstant cross-sectional configuration along its entire length, it isrecommendable to use the improved upper plate 39 shown partially inFIGURE 10, in place of that denoted 27 in FIGURE 6. According to ourpractical experiments, dimensions for a, b and 0 may preferably be asfollows:

In the spinneret assembly proposed by the present invention, the bottomor spinneret plate 13 (FIGURE 2), 28 (FIGURE 6) and 40 (FIGURE 9) may bereplaced with each other when occasion desires it. Therefore, thespinneret assembly should not be limited to those embodiments so farshown and described. It should be further noted that the third spinningmaterial may be same as the first or second material when so desired. Inthis case, the number of spinning gear pumps may be reduced from threeor two.

The conjugated sheath-core type composite filaments have generally across-sectional configuration as shown at (L) in FIGURE 12.

naterials in metered quantities, the relative cross-areas )f componentsconsisting the conjugated sheath-core type :omposite filament can beprecisely controlled for obaining a specific crimp performance whichmeans a con- ;iderable progress in the art.

When the filament is spun from only two different kinds If spinningmaterial, the number of feed pumps may be 'educed from three to two aswas already referred to. In his case, one of these pumps is preferablyarranged to :"eed the material to both inlet conduits 15 and 17, 30 1nd32 or 42 and 44. In this case, however, precise worknanship is necessaryto finish the various parts of the ipinneret, especially its passageconduits, for obtaining :pun filaments of a specifically desiredcross-section. The )ccasional filament cross-section of a specificconfiguraion as shown by way of example at (I), (I) or (K) de- Jendsupon the kind and nature of the two spinning ma- .erials to beconjointed together. The conjugated core ma- :en'al should preferablyhave a higher viscosity than that If the sheath material.

It will be easily noted from the foregoing that the filanents accordingto the invention comprise concentric :ores to the respective sheaths andthat each of the cores ment and the spun filament was wound up at aspeed of 400 m. per minute. The spun fiber 'before draft was 180 denier/10 filaments which were then subjected to a cold drawing, 3.56 times ofthe initial. The thus drawn product was finally treated in a boiledwater bath, 100 C., for 10 minutes. The product, microscopically havinga cross-sectional configuration as shown at (J in FIGURE 12, represented65 crimps per inch in the mean, thus 7 showing a satisfactory crimpperformance. In FIGURE :omprises two conjugated materials of differentphysical properties with each other, especially crimp potencies, the:onjugating surface being concave as at 104, convex as at [05 or evenstraight as at 103 and 106, as the case may e, as shown in several modelsketches in FIGURE 12. n practice, however, the conjugating surface mayrepreient a form of ripple. It will be further seen that the filanentaccordingto the invention represents various radial :rimp potenciesresulting especially from the fact that the :ore comprises two ditferentspinning materials and repre iCIltS a clear conjugating surface formedtherein.

In certain occasions, the conduit 20 may be slightly out if registrationwith the spinneret conduit 2344. This nodified design will apply to thespinnerets shown in FIGURES 5 and 9, respectively.

In the following, several numerical examples of the :pinning processaccording to this invention will be given For 'better understanding ofthe invention and in no limitng sense thereof. In these examples,relative viscosities of :olyamides are given relative to a 95.5%sulfuric acid ised for solvent. Parts are given by weight, if nototherwise specified.

EXAMPLE 1 50 parts of e-caprolactam, 25 parts of nylon 66 salt[hexamethylenediamine adipate) and 25 parts of nylon 3-10 salt(hexamethylenediamine sebacate) were introluced in an autoclave andpolymerized in the conventional vay, thus obtaining a terpolyamidehaving a relative vis- :osity of 2.5. Separately, a homopolyamideconsisting ex- :lusively of e-caprolactam and having a relativeviscosity )f 2.3 was prepared according to the conventional techuque.

For carrying out the spinning process, the spinneret :hown in FIGURESl-4 and described hereinbefore was employed. In thiscase, each thicknessof the plates 11, 12 md 13 amounted to 10 mm. The bore of each of theconluits 15, 16, '17, 18 and 20 was 1 mm. b. Bore of outlet )pening24:0.3 mm. Diameter of pitch circle passing hrough all the centers ofsaid openings: 100 mm. Num- )er of holes 24 was 10.

From a quantity of the feed pump G1, the terpolylmide, and from thepumps G2 and G3 different quantiies of the homopolyamide were fed in avolumetric ratio )f 40:40:20 to respective inlet conduits 15, 16 and 17.

The spinneret was kept at 290 C. and the material was :xtruded therefromat a rate of 8 g. per minute per fila- 12, the dotted line at 107representing a separating surface between the core and the sheath didnot appear in this case.

EXAMPLE 2 A copolymer having a molecular weight: 78,000 and obtainedfrom 91.5 parts of acrylonitrile, 8.0 parts of methyl acrylate and 0.5part of methacryl sulfonate, hereinafter called stock A, andpolyacrylonitrile having a molecular weight: 80,000, hereinafter calledstock B were prepared. As the solvent, at 70%-nitric acid, well refinedto reduce the contained nitrous acid to 0.0003%, was employed.

The first spinning material comprised only the stock A and the secondone consisted of a 60:60 mixture of said stocks A and B. For the latterpurpose, these stocks were dissolved in a proper quantity of the solventat 3 C. so as to represent a viscosity of 800 poises at 0 C.

With use of the first embodiment of spinneret assembly shown in FIGURESl-4, the first material was fed to first inlet conduit 15 and the secondmaterial supplied to both second and third conduits 16 and 17, so as toperform a composite spinning by extruding the composite material into a33% aqueous sulfuric acid kept at 3 C. The spinneret assembly wasprovided with 200 spinneret openings, each being of 0.08 mm. diameter.The take-up speed of the filaments from the coagulation bath amounted to6 m./min. The gel-state filaments were passed through a rinsing waterbath to carry out the washing to a satisfying degree and then subjectedto a stretching step in a boiling water, C., to stretch the stock 7times the original length. Upon thus stretched, the product wassubjected to a solvent treatment as usual and the filaments were driedup by passing them through an infra-red drier.

- The filament of this dried yarn represented a crosssectionalconfiguration as shown at (I) in FIGURE 12. By steaming at C. for 10minutes, 67 crimps developed in the mean on the filament per inch.Separating surface shown therein at 108 was not apparent.

EXAMPLE 3 Using the modified spinnert assembly shown in FIG- URES 5-7,nylon-6 polymer used in Example 1 was fed to first inlet conduit 30 andthe copolymer used in the same prior example was supplied under pressureto second inlet conduit 31, while nylon-66 polymer (hexamethylenediamineadipate) having a relative viscosity 2.5 was fed to third inlet conduit32 for performing a composite spinning while using, as before, threedifferent spinning pumps. The feed rate ratio was 25:25:50. Thespinneret assembly was held at 290 C. and the conjugated filaments wereextruded at a rate of 8 g. per minute per filament and taken up at 400m./min. The titer of the undrawn yarn was 180 denier/ 10 filaments. Thethus obtained undrawn yarn was subjected to a drawing step forincreasing the original length to 3.56 times using a hot plate at C. andthe drawn yarn was then treated in a boiling water bath, 100 C., for 10minutes, for developing curled crimps, 66 crimps per inch in'the mean.When this yarn was dyed with an acid dyestufi, Alizarin Brilliant SkyBlue R (manufactured by Farbenfabriken Bayer, Leverkusen, Germ ny), aclear and dark colored product was obtained. Cross section, see (K).

9 EXAMPLE 4 A polypropylene polymer and a propylene ethylene randomcopolymer containing 7 mol percent of ethylene were conjugatedly spunthrough the modified splnneret assembly shown in FIGURES -7. Morespec1fically, said polypropylene polymer was fed to the first and thirdinlet conduits 30 and 32, while said propylene ethylene random copolymerwas fed to the second inlet conduit 31 The spinneret assembly was heldat 290 C. and thespmmng material was extruded at a rate of 4.6 g. perminute per filament and taken up at 184 in. per minute. In this case,feed pumps were three in number and the feed rates to inlet conduits 30,31 and 32 was kept at a ratio of 45:45:10. The undrawn yam represented225 denier/ 12 filaments. This undrawn yarn was drafted to 2.45 times inlength by means of a hot plate at 130 C. and then subjected to atreatment in a boiling water bath, 100 C., for minutes, therebydeveloping satisfactory CI'll'IlPS, such as 65 crimps per inch in themean. The cross-sectional configuration of each filament was that shownin FIG- URE 12 at (I). Separating surface at 108 was not apparent.

EXAMPLE 5 While using the last embodiment of the spinneret assemblyshown in FIGURES 8-11, nylon-6 polymer having a relative viscosity of2.3 was fed to first inlet conduit 42 and a terpolyamide comprisinge-caprolactam 80 mol percent, nylon-66 salt 10 mol percent and nylon-6Tsalt (hexamethylenediamine terephthalate) 10 mol percent, having arelative viscosity of 2.4 was supplied to second inlet conduit 43, whilenylon-6 polymer was fed to third inlet conduit 44 by means of respectivefeed pumps. The feed rate was 3:312. Extrusion was made through outletopenings 49. Spinning velocity was 1000 m./min. at 290 C. The spunundrawn yarn represented 480 denier/ filaments. With use of hot pin keptat 130 C., the yarn was drafted to 4.3 times of length, thusrepresenting 110 denier.

The spun and drafted yarn was wound up onto a bobbin and then rewoundinto a skein, which represented no crimps. This skein was dipped in aboiling water bath, 100 C., for 20 minutes. The thus treated yarnrepresented the following crimp characteristics.

Number of crimps: 53 per inch (in the mean) Crimp elongation: 135% Crimpelongation= X 100 (percent) Where L is the length of filament under theinitial stress condition (2 mg./denier); L is the elongated length ofthe same filament when an increased load, 50 mg./ denier, was applied.

The above definition will apply to Example 6 to be given. Themicroscopic cross-sectional configuration of each of the filaments inthis case is schematically shown in FIGURE 12 at (I).

In comparison with the results in this case, a comparative experimentwas carried out in such a way that nylon 6 and a terpolyamide which havebeen referred to in Example 5 were conjugatedly spun from a comparativeconventional side-by-side type spinneret. When the spun filaments weretreated in a boiling water bath, a considerable sticking betweenfilaments took place and could not provide crimped one.

EXAMPLE 6 Nylon 6 of the polymer disclosed in the foregoing example wasreplaced by nylon 66 having a relative viscosity of 2.4. The spinningconditions were same as before, except that the spinneret was kept at285 C.

The conjugatedly spun goods were finally subjected to a treatment in aboiling water bath, thereby developing the following crimpcharacteristics:

Number of crimps: 55 per inch (in the mean) Crimp elongation: 113% Thegoods were beautiful colored bulky yarns which were substantially equalin quality to false twisted bulky yarn of nylon 66.

EXAMPLE 7 Nylon 66 as the first spinning material was fed to first inletconduit 15 of the first spinneret embodiment shown in FIGURE 2, acopolymerized polyamide, as the second spinning material, prepared frome-caprolactam and nylon 66 salt in a ratio of 55:45 was supplied tosecond inlet conduit 16, while nylon-6, as the third spinning material,having a relative viscosity of 2.3, was fed to third inlet conduit 17,for carrying out a conjugated spinning process as before. Volumetricfeed ratio among said three spinning materials was set to /3 1%. Thespinning temperature was 280 C., the spinning velocity: 850 m./min.; thede gree of drawing: 3.85 times; the temperature of hot plate: C. Thethus spun and drawn goods represented 70 denier/24 filaments.

The microscopic cross-sectional configuration is shown in FIGURE 12 at(L). When the spun and drawn goods were subjected to a heat treatment ina boiling water bath, they developed beautiful and remarkable crimps,which products were highly adapted for use as knitting yarns.

As will be noted from the foregoing, the novel manufacturing processaccording to this invention for providing conjugated sheath-core typecomposite fibers may be carried into effect through the way of meltspinning, dry spinning or wet spinning, as occasion may desire.

It should be further noted that the nature and kind of the spinningmaterial can be vastly altered or modified, practically there being nolimitation in the selection.

Although only three embodiments are shown and described for illustrativepurpose of the apparatus according to this invention, there may be madeconsiderable change and modification thereto, so far as theaforementioned principles of the invention are embodied.

What we claim is:

1. A spinneret. assembly for the manufacture of conjugated sheath-corecomposite filament comprising upper plate means and lower plate meansdisposed in superimposed relation, at least one pair of separate inletpassages in said upper plate means for receiving two different corecomponent materials, at least one spinning orifice extending throughsaid lower plate means, said pair of inlet passages communicating withsaid spinning orifice with the outlet openings of said inlet passagesbeing disposed in substantial alignment with said spinning orifice,additional passage means extending through said upper plate means forreceiving a sheath material, recess means formed in said lower platemeans about the inlet for said spinning orifice and disposed incommunication with the outlet end of said additional passage whereby thetwo dilferent core component materials will be fed in conjugatedrelation to said spinning orifice and coated with said sheath materialupon passage through said recess means prior to being extruded throughsaid spinning orifice.

2. A spinneret assembly as set forth in claim 1 wherein said upper platemeans is comprised of a first upper plate and a second lower plate withsaid pair of inlet passages and said additional inlet passage extendingthrough said first upper plate, second recess means in the upper surfaceof said second lower plate in communication with said pair of inletpassages, single outlet passage means extending through said secondlower plate in communication between said first and second recess means.

3. A spinneret assembly as set forth in claim 1 further comprisingconcentric projecting ring means disposed in said first recess meansabout said spinning orifice to divide said first recess means into anouter ring zone in communication with said additional inlet passage andan inner disc-like zone in communication with said pair of inletpassages.

4. A spinneret assembly as set forth in claim 1 wherein said pair ofinlet passages are disposed at an angle to each other with the outletends of said passages intersecting at the lower face of said upper platemeans.

5. A spinneret assembly as set forth in claim 4 further comprisingannular projection means surrounding said spinning orifice and having aheight less than the depth of said first recess means to define an outerannular recess in communication with said additional inlet passage.

References Cited UNITED STATES PATENTS 2,386,173 2/1945 Kulp et al. 1882,822,574 2/1958 Lavash.

3,006,028 10/1961 Calhoun 18--8 3,014,237 12/1961 Breen 188 3,117,3621/1964 Breen.

3,320,633 5/1967 Cancio et a1 18-8 3,397,427 8/1968 Burke et al. 18-8WILLIAM J. STEPHENSON, Primary Examiner

